Acute myocardial infarction is a rare event in pregnant patients. Mechanical valves are naturally thrombogenic and require careful anticoagulation. Pregnancy produces a hypercoagulable situation and necessitates close follow-up in pregnant patients with mechanical heart valves. We present a 34-year-old pregnant woman who had mitral and aortic valve prosthesis. She developed resistant pulmonary oedema in the post-partum period after myocardial infarction. Oxytocin was used in this patient to induce midterm labour and prevent post-partum bleeding. Issues surrounding management of pulmonary oedema and use of oxytocin therapy during pregnancy are discussed. We emphasize the need for awareness of this condition and call attention to the risk of pulmonary oedema during labour.